Will the upgrades work if you are upgrading from 1.1.8 to 2.0RC?
Umm, yes. You need to use the large upgrade pack though. There are three packs available.
"Update" is for going from 2 beta 4 to RC1.
"Upgrade" is for upgrading from 1.1.8, or from 2 beta 4 if it is using mods.
"Install" is what it says.
MY advice: remove all mods from your 1.1.8 forum before running the upgrade.
Ok, and another question, how much has the SSI changed as far as function names go?
No idea. I don't know anything about SSI.
Yes, there are changes.
(and a few new parameters that can be used with them).
eg ones where you could only exclude boards, now have an include boards parameter aswell (which may affect their ordering).